Fresh shots were fired in the war between low-cost airline Ryanair and passenger watchdog the Air Transport Users Council last week.

Michael O'Leary, the Irish carrier's chief executive, denounced the ATUC as 'a bunch of halfwits' when asked why Ryanair refuses to respond to representations from the watchdog - which is attached to the Civil Aviation Authority and takes up cases from passengers unhappy with the way an airline handled their complaint.

Ryanair and the ATUC have not been on speaking terms for 18 months now.

In this case a college lecturer, Sue Hollinrake, complained that Ryanair's Stansted check-in staff were rude and refused to pass a message to her husband David Tune (who was stuck in traffic) that she would leave his passport at Left Luggage for him to collect, so she and her daughters could take their booked flight to Glasgow Prestwick and he could buy a fresh ticket for the next one.

She and the girls were forced to wait for him and buy four new tickets.

Complaints to Ryanair received no reply, and a letter to ATUC brought the response that it could not help because Ryanair has told its staff not to answer ATUC correspondence.

O'Leary defended accusations that his airline was graceless to complainants, saying it was 'robust'.

The airline and the watchdog first fell out after the ATUC reported Ryanair to the Office of Fair Trading for refusing to compensate passengers whose luggage it damaged - won the case and made it public. ATUC chief executive Simon Evans said he would publish a complaints league table in August and Ryanair would be 'well represented'.